Introduction
As systems grow, code becomes harder to manage.
Packages help organize everything into one place.
What a Package Does
A package groups:
- procedures
- functions
- variables
into a single unit.
Basic Structure
CREATE OR REPLACE PACKAGE emp_pkg IS
PROCEDURE hire_employee(p_id NUMBER, p_name VARCHAR2);
FUNCTION get_salary(p_id NUMBER) RETURN NUMBER;
END emp_pkg;
/CREATE OR REPLACE PACKAGE BODY emp_pkg IS
PROCEDURE hire_employee(p_id NUMBER, p_name VARCHAR2) IS
BEGIN
INSERT INTO employees VALUES (p_id, p_name);
END;
FUNCTION get_salary(p_id NUMBER) RETURN NUMBER IS
v_salary NUMBER;
BEGIN
SELECT salary INTO v_salary FROM employees WHERE id = p_id;
RETURN v_salary;
END;
END emp_pkg;
/How This Looks in Practice
In a real system, you might have:
User package:
- create user
- disable user
- reset password
Finance package:
- calculate tax
- process payments
Each package handles a specific part of the system.
Why This Helps
Packages:
- keep code organized
- make updates easier
- allow reuse
- hide internal logic
Only what is defined in the package interface is visible.
In Larger Systems
Instead of giving direct access to database tables, systems often expose only package functions.
This helps control how data is accessed and modified.
Conclusion
Packages are used to organize and control code as systems grow.
They make projects easier to manage and maintain.